Madrid -LRB- CNN -RRB- -- Spanish police have arrested 750 people after a nationwide investigation into fake businesses , according to a statement Wednesday .

The mass arrests were part of a crackdown on a scam through which $ 28 million of public funds were paid out for Social Security benefits , according to the police statement .

Police targeted fake companies operating in tourism , construction , industrial cleaning and package delivery , and made the arrests over recent months .

`` Among those arrested are 30 managers of the fake companies who , without any real business activity , registered people for Social Security to illicitly obtain benefits , or to obtain residency or working permits for foreign citizens , '' the police statement said .

A total of 8,400 people were registered on Social Security rolls as part of the scam , and in 2,100 cases , they received some form of government payout . In addition , 362 foreigners were able to get working or residency papers in Spain through the fraud , the police said .

The investigation uncovered 4,000 crimes of document and other fraud linked to the payments from public funds .

More than half of the 750 arrests were made in Madrid and Barcelona , but there were also dozens of arrests each in the cities of Almeria , Alicante , Jaen , Granada , Valencia and Guadalajara .

The operation , which the police said was the largest to date , represents about half the arrests made in the past year to crackdown on such fraud . Police say it has cost the state a total of $ 64 million . The police statement did not detail how they would recover the money or revoke fraudulent working papers .

The Labor Ministry press office said the 8,400 people falsely added to social security rolls were recorded as part of the government 's employment statistics . But they are likely to have had little impact on the real statistics , which show 5.9 million Spaniards out of work and the unemployment rate at 25.9 % .

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Spanish police have arrested 750 people after a nationwide investigation into fake businesses

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The crackdown comes as part of a year-long probe into benefit fraud , which has cost $ 64 million

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Policy say investigation uncovered 4,000 crimes of document and other fraud of public funds